Modern society bases most of its transportation infrastructure on the internal combustion engine. From automobiles to airplanes, the internal combustion engine drives much of commerce. Generally, the internal combustion engine uses the combustion of a fuel source with an oxidizer to generate gases under high pressure. The design of most internal combustion engines direct these gases against a mechanical component. This causes the mechanical component to move, converting the combustion process into mechanical energy harnessed to perform work. These engines can vary greatly in size and be used in numerous applications.
A cycle consisting of four events generally describes the basic operation of an internal combustion engine. These events are intake, compression, power (ignition), and exhaust. During intake, a fuel source, such as gasoline, and an oxidizer, such as air, are drawn into, or pumped into, a combustion chamber through valves operated by a camshaft. The two combustible ingredients, the fuel source and the oxidizer, mix within the combustion chamber. Next, compression occurs. During compression, the combustible ingredients are placed under pressure. Usually a piston, the maximum range of motion of which is controlled by a crankshaft to which the piston is attached, moves into the combustion chamber, decreasing the volume of the combustion chamber and placing the fuel source and oxidizer under great pressure. At the point of greatest compression, an igniter, such as a spark from a spark plug, ignites the combustible ingredients causing the rapid conversion of the combustible ingredients into a rapidly expanding gas. This rapidly expanding gas generates a force against the piston causing the piston to move in a manner that increases the volume of the combustion chamber. It is this motion that generates mechanical energy harnessed through the crankshaft and other components. Finally, the piston reaches the maximum range of expansion as determined by the crankshaft. As the crankshaft turns it pushes the piston back into the combustion chamber where the combustion gases exhaust through a valve opened through operation of the camshaft. In different variations of the internal combustion engine, the events can be combined in certain specific ways to create engines that better fit certain applications.
As ubiquitous as the internal combustion engine is, it also suffers from some serious drawbacks. For example, because the internal combustion engine must operate at high pressures, the components must be extremely strong, necessitating heavy overbuilt components, or lightweight expensive components. Heavy components decrease the efficiency and use of the engine, and lightweight components drive up the cost of the engine limiting, the number of applications to which it can reasonably be applied. Thus, there is a need for a combustion engine that does not need to operate at such high pressures.
The high pressures can also necessitate that the engines be finely tuned, and limited to one particular type of fuel so that a specific pressure, fuel, and oxidizer must be used at all times. This limits the applications to which any individual engine can be placed. Furthermore, it increases the dependence of the those using the engine on a particular fuel source. Thus, there is a need for combustion engines, where a user can easily convert any individual engine to run on multiple fuel sources depending on what is available, and the type of work that is to be performed.
Finally, regardless of the type of components, internal combustion engines must operate a crankshaft and camshaft assembly to successfully complete the engine cycle that generates power. Operation of these components is necessary to continue the operation of the engine; yet, with each cycle, power that could otherwise be directed to the purpose of the engine is leached by these components. This decreases the engine's efficiency and drives up the cost of operation through increased fuel costs. Thus, there is a need for a combustion engine that decreases efficiency losses due to components such as the crankshaft and camshaft.